The Chassis Performance Analysis And Test Of The Four Crawler Type Sugarcane Harvester

China is a great power of sugarcane production.Sugarcane harvest mainly depends on manual chopping and collecting,and the rate of harvesting by machine is less than 2%,which brings about that the sugarcane output cost stays in a high position without going down.Sugarcane fields in the main locality of growth of sugarcane,Guangxi,Yunan,and alike,are mainly hills and mountains.It is of practical significance to design a sugarcane harvester that can adapt to hilly and mountainous areas.The team designed a new triangular caterpillar sugarcane harvester.The chassis of this machine was a four-pedrail running system that was made up of a front triangle caterpillar wheel and a rear flat caterpillar wheel,and the rear caterpillar track yawed and steered.This paper analyzed the structural parameters of the machine theoretically,set up its multi-body dynamic model,and simulated its dynamics performance under different parameters in software.Three tests,that is,horizontal driving,slope driving and obstacle-crossing driving,were applied into its proto respectively to verify it.The research finding in this paper could provide a basis for improving the model.The main research content and conclusion are as follows:(1)Analysis and research on rideability parameters.Rideability parameters were mainly analyzed,such as the longitudinal gradient stability and barrier-crossing performance of the triangular caterpillar sugarcane harvester.(2)The experiments of virtual prototype and physical prototype were carried out.A three-dimensional modeling software,namely,Pro/Enginee,and a multibody dynamics software,namely,Recur Dyn,were used for design and modeling of the sugarcane harvester.A virtual prototype model of the sugarcane harvester was completed in the multibody dynamics software interface.A terrain model of hills and mountains was built,and kinetic parameters of the sugarcane harvester were analyzed and studied.Finally,complete the triangular crawler sugarcane harvester machine modeling dynamic model.In multibody dynamics simulation software Recur Dyn terrain model is also established.(3)Simulation and test of driving on a flat hard road.In the case of a flat hard road,it was tested that the speed could go far as to be 2 km/h or so when the whole vehicle was at high speed gear,and 1.5 km/h or so when at low speed gear.When running straight horizontally on a flat road surface,a no-load vehicle was able to ride smoothly without any serious sliding and heeling phenomena under different acceleration states.A full-load vehicle was better than a no-load vehicle in the aspect of stable ride of the whole machine,but in a higher demand for vehicle power.Under full load,the sliding of vehicle caterpillar track increases so that driving at a low-speed gear should be chosen when the sugarcane harvester was full-loaded,given consideration to stable ride and efficiency.(4)Simulation and test of driving on a ramp road surface.When the selected longitudinal gradient was 9 degrees,the sugarcane harvester could run over it and the vehicle had power enough to run forward.The speed of high and low gear was kept at 0.5 m/s and 0.385 m/s respectively.In the state of longitudinal uphill,a no-load vehicle had good dynamics performance,yet with high vehicle vibration.The vibration area was mainly centered on the sugarcane-collecting box of the vehicle.Full loaded,the vehicle ran more stable and smooth,the variation amplitude of the yaw angle didn’t go beyond the vehicle’s endurance scope.Overall stability occurred when the vehicle ran at a lateral slope of 8 degrees.In actual testing,changes in other external factors would aggravate the stability of the vehicle on a lateral slope,and increase the possibility of rolling over.(5)Simulation and test of obstacle-crossing ability.The vehicle could stride over solid barriers up to eighteen cm in height.Compared with simulation data,amplitude variation of the actual measured pitch angle,yaw angle and roll angle was rather big,vehicle pitch angle fluctuation amplitude was more than 5°,the pitch phenomenon of the whole vehicle was rather obvious;the amplitude variation of roll angle was up to 3°,other elements that brought about pitch angle change of the vehicle needed to be taken into account when the vehicle leaped over an obstacle.When striding over a trench with a width of 50 cm and a height of 30 cm,it passed safely.The roll angle of the vehicle changed obviously,the maximum difference of the amplitude was 2°,which indicated that the bump of the left and right caterpillar tracks of the vehicle was rather serious at this moment.